Deterioration of Basalt Fiber in Cementitious Material and Mitigation with Basalt Powder

Although basalt fiber (BF) has been used to reinforce cement composite as an eco-friendly material, its effect on basalt fiber-reinforced cement composite (BFRCC) is contradictory. BF was found to be corroded by a pore solution through scanning electron microscopy observation. Owing to the chemical alkali corrosion and physical denudation of the BF in an alkaline environment, the interface bonding between the BF and the cement matrix was weakened, and the toughening effect of the BF could not be fully exerted. Pore structure characterization was examined based on the water uptake kinetics method and image analysis of binary specimen slices. The BF was found to have a detrimental effect on the pore structure because of the inclusion of exogenous bubbles. However, basalt powder (BP) could densify the pore structures of the cementitious materials, especially in the basalt-powder-fiber-reinforced cement composite (BPFRCC), in which it further reduced the corrosion degree of the BF and enhanced the bonding between the BF and cement matrix interfaces. Therefore, BP and BF can synergistically enhance the performance of BPFRCC.